The typical indoor environment is not the best for growing herbs. It's difficult to provide enough sunlight or humidity without some extra equipment.

The potting medium that those young plants come in is not the best, either. And, to add to everything else, any grocery store herb I've casually inspected has had spider mites.

Why not find a nice, sunny location in your own yard to grow a few plants? It doesn't have to be a separate garden.

Herbs can be grown in two distinctly different ways.

(1) For the garden. These plants are grown at close-to-normal rates, and always come in pot sizes suitable for the stage of growth. This ensures a healthy root system, the key to long-term plant health.

(2) For the kitchen, and to use in the short-term only. These plants are force-grown with a diet very high in nitrogen to increase the foliage size and rate of growth. They come in very small pots - much smaller than you'd expect for the size of the above-ground parts. You'll always find that the roots are potbound. It's simply a method of keeping the leaves fresher than if cut off the plant, but it's not intended as a long-term plant.

Sometimes you can be lucky and produce a healthy plant from the latter type, but in most cases the best you can expect is a stunted plant. Once a root has been squashed or bent, it stays that way, and it's a bit like trying to drink through a bent or crushed straw. Can't be done. If the plant can manage to grow new roots in a non-cramped environment, it'll be those which allow the water and nutrients to get through where they're needed. But the plant will always be under some stress.

In short - best to buy your plants from a reputable plant nursery if you want to grow them on. Before buying a plant, tip it upside down and remove it from the pot to check that the root system is not too crowded. If you see roots growing around the pot, not straight down - don't buy it.

Only buy the supermarket version if you want fresh herbs for a couple of weeks or so.

And yes, of course, any plant will be much happier outside where it's supposed to be! Most can be grown in pots, but you must provide a size of pot that's big enough to accommodate a growing root system. When the roots fill up the pot (so that there's not much soil left relative to the amount of roots), it's time for a bigger pot.

I have a very rough (and bendable!) rule of thumb. When choosing a pot, imagine planting the plant upside down. If you think the top part will fit into the pot comfortably, then you can be sure that the root system will fit!

Cilantro dies normally just after it blooms so you will be lucky if it lives a month. Start purchasing seeds to put in the pots. Even in the garden cilantro does not live very long. You are wasting your money buying it in a pot.

Ack! Ok, I do grow herbs outside every summer pretty successfully--but had read in numerous places about "cooking herbs growing on the windowsill" that I thought it was possible to keep them going in the house during the winter. Guess those were over-romanticized accounts!

I won't waste any more money on herbs from the grocery store, thanks.

Cilantro is one of those herbs that grow 'one time'. You cut it, use it in your culinary dishes and that is it, so best to grow by seed (not by store plant) and plant the seeds several weeks apart so they don't all grow at once. Cilantro prefers cooler weather and not much direct sun. Heat will cause it to bolt and at that point it does not taste the same nor look as pretty, BUT, if you let it grow (bolt) to seed you will get many many seeds to plant all over again. If you use a lot in cooking, then you may want to plant in the ground vs. in pots. It takes practice, but once you get going you will never need to buy them in pots.